SEOUL, April 29 (Reuters) - North Korea test-fired a ballistic missile on Saturday from a region north of its capital, but it appears to have failed, South Korea's military said, defying intense pressure from the United States and the reclusive state's main ally, China.

An official at South Korea's Joint Chiefs of Staff confirmed the launch but did not immediately have any further information. Yonhap news agency said the missile appeared to have blown up a few seconds into flight.

The test came as U.S. Secretary of State Rex Tillerson warned the United Nations that failure to curb North Korea's nuclear and ballistic missile programs could lead to 'catastrophic consequences'.

U.S. President Donald Trump told Reuters in an interview on Thursday a "major, major conflict" with North Korea was possible over its nuclear and ballistic missile programs.

But both China and Russia rebuked Washington's threat of military force at a meeting of the U.N. Security Council on the matter.

Chinese Foreign Minister Wang Yi told the 15-member council it was not only up to China to solve the North Korean problem.

"The key to solving the nuclear issue on the peninsula does not lie in the hands of the Chinese side," Wang told the council in blunt remarks that Tillerson later rebuffed.

Tensions on the Korean peninsula have been rising as North Korea celebrates a number of key anniversaries, with both sides staging major military drills.

In a show of force, the United States is sending the USS Carl Vinson aircraft carrier group to waters off the Korean peninsula, where it will join the USS Michigan, a nuclear submarine that docked in South Korea on Tuesday. South Korea's navy has said it will hold drills with the U.S. strike group. (Editing by James Dalgleish and Lincoln Feast)